Atlantoaxial interlaminar distances in cervical flexion in children

2003 ◽  
Vol 98 (3) ◽  
pp. 271-274 ◽  
Author(s):  
R. Shane Tubbs ◽  
Matthew D. Smyth ◽  
John C. Wellons ◽  
Jeffrey P. Blount ◽  
Paul A. Grabb ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Atlantoaxial Instability ◽  
Entire Group ◽  
Content Type ◽  
Significant Difference ◽  
Full Flexion ◽  
The Mean ◽  
Atlas And Axis ◽  
Fine Print ◽  
Posterior Elements

Object. To the best of the authors' knowledge, no quantitative analysis of the atlantoaxial interlaminar distance in flexion (ILD) in children exists in the medical literature. In this study they sought to determine the age-matched relationship between the posterior elements of the atlas and axis in children in cervical spine flexion, to be used as an adjunct to the atlantodental interval in common clinical use. Methods. Lateral radiographs of the cervical spine in full flexion were analyzed in 74 children. The atlantoaxial ILD was defined as the distance between a midpoint of the anterior cortices of the atlantal and axial posterior arches. The mean ILD for the entire group was 19 mm (range 8–30 mm). No significant difference was seen between male and female patients (p = 0.084). When stratified by age, the mean ILD was 12.3 ± 3 mm (15 cases) in children age 3 years or younger and 20.5 ± 4.7 mm (59 cases) in children age older than 3 years. Further stratification of the groups yielded a mean ILD of 10.4 ± 1.4 [eight cases]) in children age 1 to 2 years, and 14.4 ± 4.7 mm (seven cases) in children age 3 years. In children older than 3 years of age the mean ILD was consistently approximately 20 ± 5 mm regardless of age. Conclusions. Rapid, safe, and accurate diagnosis of the cervical spine is essential in critical care. Knowledge of the distance between the posterior elements of the atlas and axis in flexion should enhance the clinicians' (those who clear cervical spines) ability to diagnose accurately atlantoaxial instability on lateral radiographs obtained in flexion.

Gamma knife radiosurgery for intracranial metastatic melanoma: a 6-year experience

2002 ◽  
Vol 97 ◽  
pp. 494-498 ◽  
Author(s):  
Jorge Gonzalez-martinez ◽  
Laura Hernandez ◽  
Lucia Zamorano ◽  
Andrew Sloan ◽  
Kenneth Levin ◽  
...  
Keyword(s):  
Prognostic Factors ◽  
Brain Metastases ◽  
Metastatic Melanoma ◽  
Gamma Knife Radiosurgery ◽  
Tumor Control ◽  
Karnofsky Performance Scale ◽  
Content Type ◽  
Significant Difference ◽  
The Mean ◽  
Fine Print

Object. The purpose of this study was to evaluate retrospectively the effectiveness of stereotactic radiosurgery for intracranial metastatic melanoma and to identify prognostic factors related to tumor control and survival that might be helpful in determining appropriate therapy. Methods. Twenty-four patients with intracranial metastases (115 lesions) metastatic from melanoma underwent radiosurgery. In 14 patients (58.3%) whole-brain radiotherapy (WBRT) was performed, and in 12 (50%) chemotherapy was conducted before radiosurgery. The median tumor volume was 4 cm3 (range 1–15 cm3). The mean dose was 16.4 Gy (range 13–20 Gy) prescribed to the 50% isodose at the tumor margin. All cases were categorized according to the Recursive Partitioning Analysis classification for brain metastases. Univariate and multivariate analyses of survival were performed to determine significant prognostic factors affecting survival. The mean survival was 5.5 months after radiosurgery. The analyses revealed no difference in terms of survival between patients who underwent WBRT or chemotherapy and those who did not. A significant difference (p < 0.05) in mean survival was observed between patients receiving immunotherapy or those with a Karnofsky Performance Scale (KPS) score of greater than 90. Conclusions. The treatment with systemic immunotherapy and a KPS score greater than 90 were factors associated with a better prognosis. Radiosurgery for melanoma-related brain metastases appears to be an effective treatment associated with few complications.

Ventricular volume change in childhood

2002 ◽  
Vol 97 (3) ◽  
pp. 584-590 ◽  
Author(s):  
Chris Xenos ◽  
Spyros Sgouros ◽  
Kalyan Natarajan
Keyword(s):  
Statistical Difference ◽  
Linear Regression Analysis ◽  
Ventricular Volume ◽  
Intracranial Volume ◽  
Normal Children ◽  
Content Type ◽  
Ventricular Volumes ◽  
Significant Difference ◽  
The Mean ◽  
Fine Print

Object. The aim of this study was to construct a model of age-related changes in ventricular volume in a group of normal children ages 1 month to 15 years, which could be used for comparative studies of cerebrospinal fluid circulation disorders and cerebral atrophy developmental syndromes. Methods. A magnetic resonance imaging—based segmentation technique was used to measure ventricular volumes in normal children; each volume was then plotted against the child's age. In addition, intracranial volumes were measured and the ratio of ventricular to intracranial volume was calculated and plotted against age. The study group included 71 normal children, 39 boys and 32 girls, whose ages ranged from 1 month to 15.3 years (mean 84.9 months, median 79 months). The mean ventricular volume was 21.3 cm3 for the whole group, 22.7 cm3 in boys and 19.6 cm3 in girls (p = 0.062, according to t-tests). The mean ventricular volume at 12 months for the whole group was 17 cm3 (20 cm3 in boys and 15 cm3 in girls), representing 65% of the volume achieved by 15 years of age (87% in boys and 53% in girls). The volume increased by a factor of 1.53, to 26 cm3 (23 cm3 in males and 28 cm3 in females, increase factors of 1.15 and 1.86, respectively) at 15 years of age. The change in ventricular volume with age is not linear, but follows a segmental pattern. These age periods were defined as: 0 to 3, 4 to 6, 7 to 10, and 11 to 16 years. A statistical difference based on sex was only demonstrated in the first 6 years of life. The mean ventricular volume for the first 6-year period was 22.4 cm3 in boys and 15.7 cm3 in girls, and the difference was significant for the two sexes (linear regression analysis for age and sex, significant according to analysis of variance regression at 0.007, p = 0.108 for age, p = 0.012 for sex). Thereafter, there was no significant difference in ventricular volume between boys and girls with further growth. The ratio of ventricular volume to intracranial volume was 0.0175 for the whole group, 0.017 in boys and 0.018 in girls (p = 0.272, according to t-tests). At 12 months of age the ratio was 0.019; it stabilized to 0.015 at 8 years of age, and increased to 0.018 at 15 years of age. No statistical difference based on sex was demonstrated with growth. Conclusions. The ventricular volume in normal children increases with age by a factor of 1.5; the increase is in a nonlinear segmental pattern. Boys have significantly higher ventricular volumes only in the first 6 years of life. The ventricular/intracranial volume ratio remains stable throughout childhood.

Results of degenerative spondylolisthesis treated with posterior decompression alone via a new surgical approach

2001 ◽  
Vol 95 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Tomoaki Kinoshita ◽  
Isao Ohki ◽  
Kenneth R. Roth ◽  
Kageharu Amano ◽  
Hideshige Moriya
Keyword(s):  
Japanese Orthopaedic Association ◽  
Degenerative Spondylolisthesis ◽  
Spinal Instability ◽  
Content Type ◽  
Significant Difference ◽  
Potential Alternative ◽  
The Mean ◽  
New Surgical Technique ◽  
Fine Print

Object. The purpose of this study was to assess radiologically demonstrated results and clinical outcomes in patients with degenerative spondylolisthesis who underwent posterior decompressive surgery via a new (unilateral) approach. This approach allows surgeons to perform central and bilateral decompression while only stripping the muscles unilaterally, thus preserving the posterior osteoligamentous complexes. Methods. The authors evaluated 51 consecutive patients in whom surgery was performed between 1987 and 1996. The mean follow-up period was 4.7 years. There was no statistically significant difference between the pre- and postoperative measurements in percentage of vertebral slippage. Postoperative dynamic angulation statistically decreased compared with its preoperative value (p < 0.05). Improvement of an average of 67% was shown on the Japanese Orthopaedic Association scale, and in 78% of these patients, good to excellent results were demonstrated. Secondary fusion was required in only three patients (5.9%). Conclusions. This new surgical technique offers a potential alternative for the treatment of degenerative spondylolisthesis in a minimally invasive manner, avoiding the risk of causing or aggravating postoperative spinal instability.

Effects of cervical spine posture on axial load bearing ability: a biomechanical study

2001 ◽  
Vol 94 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Tunç Öktenoǧlu ◽  
A. Fahir Özer ◽  
Lisa A. Ferrara ◽  
Niteen Andalkar ◽  
Ali Çetin Sarioǧlu ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Failure Modes ◽  
Failure Time ◽  
Time To Failure ◽  
Content Type ◽  
Group I ◽  
Piston Displacement ◽  
Significant Difference ◽  
Load To Failure ◽  
Fine Print

Object. The authors conducted a study to assess the effects of cervical posture on the loadbearing ability of the cervical spine. Methods. Twelve cervical spine specimens obtained in 12 adult sheep were tested. The specimens were randomly separated into two groups. In Group I the specimens were fixed in a lordotic posture, and in Group II they were fixed in a straight posture. Axial compressive loads were applied at a constant rate of 5 cm/minute. Load-to-failure, time-to-failure, piston displacement at failure, and failure modes were recorded. Statistical analyses were performed to detect differences between the groups. There was no significant difference in load-to-failure values between the two groups. However, the time-to-failure and the piston displacement values for the straight spines were significantly less than those for the lordotic spines. Additionally, the straight spines failed predominantly through ventral elements, whereas the lordotic spines predominantly failed dorsally. Conclusions. It is concluded that a loss of a lordosis increases the risk of injury to the cervical spine following axial loading.

Swan-neck deformity secondary to osteomyelitis of the posterior elements of the cervical spine

1979 ◽  
Vol 50 (3) ◽  
pp. 388-390 ◽  
Author(s):  
Ghaus M. Malik ◽  
Alvin H. Crawford ◽  
Robert Halter
Keyword(s):  
Cervical Spine ◽  
Cervical Vertebrae ◽  
Cervical Fusion ◽  
Content Type ◽  
Halo Traction ◽  
Posterior Cervical Fusion ◽  
Swan Neck Deformity ◽  
Fine Print ◽  
Posterior Elements ◽  
Excellent Stability

✓ A case of osteomyelitis is described, involving the posterior elements of the cervical vertebrae in a 7-year-old girl and resulting in swan-neck deformity. Treatment was initiated with antibiotics, and the patient was placed in halo traction. Eventually posterior cervical fusion was performed, which provided excellent stability and correction of the deformity.

Hydroxyapatite laminar spacers and titanium miniplates in cervical laminoplasty

2002 ◽  
Vol 97 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Takeo Goto ◽  
Kenji Ohata ◽  
Toshihiro Takami ◽  
Misao Nishikawa ◽  
Naohiro Tsuyuguchi ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Spinous Process ◽  
Spinal Tumors ◽  
Cervical Laminoplasty ◽  
En Bloc ◽  
Content Type ◽  
Hardware Failure ◽  
Fine Print ◽  
Posterior Elements

Object. The authors describe a new surgical technique for cervical laminoplasty that was performed in 25 patients. The posterior elements along with the various ligaments are removed en bloc and are stabilized in a lift-up position by placing hydroxyapatite (HA) laminar spacers and titanium miniplates and screws. The procedure and clinical results are discussed. Methods. The posterior spinal elements, including the lamina(e), spinous process(es), and various attached ligaments, are removed en bloc by incising the lamina in its lateral aspect. Trapezoid-shaped HA spacers are placed between the cut ends of the laminae or between the laminae and lateral masses bilaterally at each level. Malleable titanium miniplates and screws are used for fixation of the spacers. The fixation of transected laminae was judged to be successful. Postoperative care included application of a soft neck collar for 1 week but no further restriction of activity. Surgery-related outcome was assessed in the 21 patients who attended more than 6 months of follow up after laminoplasty. There were 18 men and three women who ranged in age from 27 to 81 years. Cervical stenotic myelopathy was demonstrated in 15 patients who underwent decompressive and expansive laminoplasty, and spinal tumors were documented in six patients who underwent a nonexpansive laminoplasty. Postoperative and follow-up computerized tomography scans demonstrated no hardware failure. Bone formation around the spacers was observed either at 6- or at 9-month follow-up examination in all 21 patients. Fusion of the reconstructed laminae was found to be completed at 12 months in all 18 patients able to attend follow up for this duration. Spinal alignment and the range of motion of the cervical spine were well preserved. In patients with stenotic cervical myelopathy, neurological and anatomical outcome of canal expansion were satisfactory. Conclusions. This technique enables rigid laminoplasty while maintaining anatomical and biomechanical integrity of posterior elements of cervical spine. Expansive and nonexpansive laminoplasty procedures are possible.

Cervical spine injuries in infants

1975 ◽  
Vol 42 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Lynn M. Gaufin ◽  
Stanley J. Goodman
Keyword(s):  
Cervical Spine ◽  
Fracture Dislocation ◽  
Hangman’S Fracture ◽  
Content Type ◽  
Cervical Spine Injuries ◽  
Spine Injuries ◽  
Hangman's Fracture ◽  
Therapeutic Considerations ◽  
Fine Print ◽  
Posterior Elements

✓ The authors point out the unique anatomical and therapeutic considerations involved in injuries of the cervical spine and cord in infants. The special problems encountered in the treatment of such patients are illustrated by three cases, a “Hangman's” fracture, a C6–7 fracture-dislocation, and an acute quadriparesis associated with dysgenesis of the posterior elements of C1–3.

Temporary vessel occlusion in spontaneously hypertensive and normotensive rats

1994 ◽  
Vol 80 (6) ◽  
pp. 1085-1090 ◽  
Author(s):  
Warren R. Selman ◽  
Sana U. Bhatti ◽  
C. Cory Rosenstein ◽  
W. David Lust ◽  
Robert A. Ratcheson
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Vessel Occlusion ◽  
Content Type ◽  
Spontaneously Hypertensive ◽  
Significant Difference ◽  
Clip Application ◽  
The Mean ◽  
Improved Design ◽  
Fine Print

✓ Temporary occlusion of an intracranial artery is frequently necessary in the surgical management of intracranial aneurysms, arteriovenous malformations, and tumors. While the risks of vessel damage associated with clip application have been lessened by improved design, the threat of ischemic damage remains. It is unclear whether multiple, brief periods of clip application are more or less safe than a single period of occlusion, and whether the underlying cerebrovascular status influences the outcome from either method. The effect of each of these paradigms (single: 1-hour occlusion; multiple: three 20-minute episodes separated by 10 minutes of reperfusion) on histopathological outcome was assessed in a middle cerebral artery (MCA) occlusion model using both normotensive and spontaneously hypertensive rats. The mean volume of infarction (± standard error of the mean) was not different between the single-ischemic (49.4 ± 17.3 cu mm) and the multiple-ischemic (42.9 ± 12.9 cu mm) episode groups of normotensive rats, whereas in the spontaneously hypertensive rats a significant difference existed between the volume of infarction for the single-occlusion group (126.7 ± 18.7 cu mm) and the multiple-occlusion group (162.4 ± 15.5 cu mm) (p < 0.05). The metabolic data obtained from spontaneously hypertensive animals did not provide an explanation for the larger infarction in that there were no significant differences between the single- and multiple-occlusion groups with respect to tissue glucose, adenosine triphosphate, or lactate levels. The results suggest that intermittent reperfusion may have different effects depending not only on the degree and duration of ischemia and reperfusion, but also on the underlying cerebrovascular status.

Titanium mesh cages for cervical spine stabilization after corpectomy: a clinical and radiological study

2003 ◽  
Vol 99 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Pradeep K. Narotam ◽  
Sarah M. Pauley ◽  
Gregory J. McGinn
Keyword(s):  
Cervical Spine ◽  
Bone Growth ◽  
Iliac Crest ◽  
Ct Scans ◽  
Titanium Mesh ◽  
Content Type ◽  
Spine Stabilization ◽  
Flexion Extension ◽  
The Mean ◽  
Fine Print

Object. Reconstruction after anterior cervical decompression has involved the use of tricortical iliac crest bone or fibular strut grafts, but has been associated with significant morbidity. In this study the authors evaluated the efficacy of titanium mesh cages (TMCs) for stability and fusion following anterior cervical corpectomy. Methods. Thirty-seven patients were prospectively evaluated during a 4-year period. The majority presented with spinal cord compression (97%) often due to cervical spondylosis (87%). The TMC was filled with iliac crest bone chips or Surgibone and stabilized by anterior cervical plates (ACPs). The changes in settling ratio, coronal and sagittal angles, and sagittal displacement were determined at 3, 6, and 12 months; immediate postoperative radiographs were used as baseline. Flexion—extension radiographs and computerized tomography (CT) scans (obtained at 1 year) were examined to assess stability, fusion, and bone growth within the TMC. Complications such as settling, telescoping, migration, and pseudarthrosis were not observed. Dynamic radiography revealed spinal stability in all patients. Cage-related complications occurred in 2.7% (TMC malplacement [one patient]), surgery-related complications in 10.8%, and graft-related complications in 21.6%. Evidence of bone growth into the TMC was documented in 16 (95%) of 17 patients on CT scans. The mean cage height—related settling rates were 4.46% at 3 months (31 patients [p = 0.066]), 3.89% at 6 months (28 patients [p = 0.028]), and 4.35% at 1 year (27 patients [p = 0.958]). The mean sagittal displacement changed by 3.9% (23 patients [p = 0.73]). The mean coronal and sagittal angles changed 2.89° (30 patients [p = 0.498]) and 2.09° (29 patients [p = 0.001]) at 1 year, respectively, or at last follow up from baseline. No significant differences in the radiological indices were seen when multilevel vertebrectomy cases were compared with single-level vertebrectomy (p = 0.221), smoking status, or age. Conclusions. Titanium mesh cages, in combination with ACPs, are safe and effective for vertebral replacement in the cervical spine.

Cannulated screws for odontoid screw fixation and atlantoaxial transarticular screw fixation

1995 ◽  
Vol 83 (6) ◽  
pp. 1095-1100 ◽  
Author(s):  
Curtis A. Dickman ◽  
Kevin T. Foley ◽  
Volker K. H. Sonntag ◽  
Maurice M. Smith
Keyword(s):  
Cervical Spine ◽  
Screw Fixation ◽  
Cannulated Screw ◽  
Atlantoaxial Instability ◽  
Cannulated Screws ◽  
Content Type ◽  
Screw Insertion ◽  
Bone Fragments ◽  
K Wires ◽  
Fine Print

✓ Cannulated screw systems use thin Kirschner wires (K-wires) that have been drilled into the bone to direct screw trajectories accurately into small bone fragments. Use of the K-wires avoids overdrilling the pilot holes and allows fixation of adjacent bone fragments during screw insertion. Hollow tools and hollow screws are inserted into the bone over the K-wires. Cannulated screw fixation is useful in the cervical spine to stabilize odontoid fractures and to treat atlantoaxial instability. This report describes techniques for successful cannulated screw insertion and methods to minimize complications. Cannulated screws have several distinct advantages compared to noncannulated screws: 1) the K-wires guide the screw position into the bone; 2) the K-wire trajectory can be repositioned easily if the original trajectory was not ideal; 3) the K-wires allow continuous fixation of adjacent unstable bone fragments; and 4) the K-wires prevent migration of unstable bone fragments during screw insertion. Complications associated with the K-wire (breakage, repositioning, and advancement) can be minimized using precise operative techniques, a specialized tool system, and intraoperative fluoroscopic monitoring. A unique cannulated screw tool system was developed specifically for upper cervical fixation to allow percutaneous drilling using long tunneling devices, tissue sheaths, drill guides, and long K-wires. These tools allow delivery of cannulated fracture-fixation screws at a low angle to the spine through long soft-tissue trajectories. Cannulated screws have significant advantages compared to noncannulated screws for fixation of the unstable cervical spine.

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